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991.
A mixture model approach to the mapping of QTL controlling endosperm traits with bulked samples 总被引:1,自引:0,他引:1
Endosperm traits are of triploid inheritance and have become a focus of breeding effort for their close relations with the
grain quality. Current methods for mapping quantitative trait loci (QTL) underlying endosperm traits are restricted to the
use of the phenotypes of single grain samples as input data set, which are often not available in practice due to the small
size of the cereal seeds. This paper proposed a statistical model for one specially tailored mapping strategy, where the marker
genotypes are obtained from the maternal plants in the segregation population and the phenotypic responses are replaced by
the trait means of composite endosperm samples pooled from each plant. It should therefore be more practical and have wide
applicability in mapping endosperm traits. The method was implemented by fitting the phenotypic means of endosperms into a
Gaussian mixture model. Both the exact and approximate Expectation-Maximization algorithms were proposed to estimate the model
parameters. The presence of the QTL was determined by likelihood ratio test statistics. Statistical power and other properties
of the new method were investigated and compared to the current single-seed method under a variety of scenarios through simulation
studies. The simulations suggest a reasonable sample size should be used to ensure reliable results. The proposed method was
also applied to a simulated genome data for further evaluation. As an illustration, a real data of maize was analyzed to find
the loci responsible for the popping expansion volume. 相似文献
992.
Cheng Hu Rong Zhang Congrong Wang Weihui Yu Jingyi Lu Xiaojing Ma Jie Wang Feng Jiang Shanshan Tang Yuqian Bao Kunsan Xiang Weiping Jia 《PloS one》2010,5(7)
Background
Single nucleotide polymorphisms (SNPs) from GCK, GCKR, G6PC2 and MTNR1B were found to modulate the fasting glucose levels. The current study aimed to replicate this association in the Chinese population and further analyze their effects on biphasic insulin secretion.Methods/Principal Findings
SNPs from GCK, GCKR, G6PC2 and MTNR1B were genotyped in the Shanghai Chinese, including 3,410 type 2 diabetes patients and 3,412 controls. The controls were extensively phenotyped for the traits related to glucose metabolism and insulin secretion. We replicated the association between GCK rs1799884, G6PC2 rs16856187 and MTNR1B rs10830963 and fasting glucose in our samples (p = 0.0003∼2.0×10−8). GCK rs1799884 and G6PC2 rs16856187 showed association to HOMA-β, insulinogenic index and both first- and second-phases insulin secretion (p = 0.0030∼0.0396). MTNR1B rs10830963 was associated to HOMA-β, insulinogenic index and first-phase insulin secretion (p = 0.0102∼0.0426), but not second-phase insulin secretion (p = 0.9933). Combined effect analyses showed individuals carrying more risk allele for high fasting glucose tended to have a higher glucose levels at both fasting and 2 h during OGTTs (p = 1.7×10−13 and 0.0009, respectively), as well as lower HOMA-β, insulinogenic index and both first- and second-phases insulin secretion (p = 0.0321∼1.1×10−7).Conclusions/Significance
We showed that SNPs from GCK, G6PC2 and MTNR1B modulated the fasting glucose levels in the normoglycaemic population while SNPs from G6PC2 and GCKR was associated with type 2 diabetes. Moreover, we found GCK and G6PC2 genetic variants were associated to both first- and second-phases insulin secretion while MTNR1B genetic variant was associated with first-phase insulin secretion, but not second-phase insulin secretion. 相似文献993.
SHP2是一种非受体型蛋白酪氨酸磷酸酶,其介导的信号转导异常与多种疾病包括肿瘤的发生和发展密切相关,对SHP2的深入研究有助于对其作用机制的阐明以及潜在药物学靶点的发现。本文简要介绍了SHP2的结构、功能及其介导的Ras/ERK信号通路,并着重阐述了SHP2与乳腺癌发展的关系。 相似文献
994.
Xia Y Chackalamannil S Greenlee WJ Wang Y Hu Z Root Y Wong J Kong J Ahn HS Boykow G Hsieh Y Kurowski S Chintala M 《Bioorganic & medicinal chemistry letters》2010,20(22):6676-6679
An analog of the thrombin receptor antagonist vorapaxar (SCH 530348) with increased aqueous solubility, compound 9c (SCH 602539), was discovered through incorporation of polar substituents on the pyridine ring of the himbacine-derived lead series. This analog retained the excellent potency, pharmacokinetic and safety properties of vorapaxar while increasing the aqueous solubility by 20-fold. Also presented are in vivo evaluations of this compound in a cynomolgus monkey platelet aggregation assay and in a Folts model of thrombosis in anesthetized monkeys. 相似文献
995.
SHI Zhaoxing* WANG Hengliang* HU Kun FENG Erling YAO Xiao HUANG Liuyu SU Guofu HUANG Peitang & HUANG Cuifen . Beijing Institute of Biotechnology Beijing China . College of Life Science Shandong Normal University Jinan China . College of Environmental Chemical Engineering Xi’an Jiaotong University Xi’an China Correspondence should be addressed to Huang Liuyu 《中国科学:生命科学英文版》2004,47(6):494-502
~~Screening and identification of Shigella flexneri 2a virulence-related genes induced after invasion of epithelial cells1. Jin, Q., Yuan, Z., Xu, J., Wang, Y., Shen, Y., Lu, W., Wang, J., Liu, H., Yang, J., Yang, P., Zhang, X., Zhang, J., Yang, G, Wu, H., Qu, D., Dong, J., Sun, L., Xue, Y, Zhao, A., Gao, Y., Zhu, J., Kan, B., Ding, K.. Chen, S., Cheng, H., Yao, Z., He, B., Chen, R., Ma, D., Qiang, B., Wen, Y, Hou, Y., Yu, J., Genome sequence of Shigella flexneri 2… 相似文献
996.
The protein DEK is an abundant and ubiquitous chromatin protein in multicellular organisms (not in yeast). It is expressed in more than a million copies/nucleus of rapidly proliferating mammalian cells. DEK has two DNA binding modules of which one includes a SAP box, a sequence motif that DEK shares with a number of other chromatin proteins. DEK has no apparent affinity to specific DNA sequences, but preferentially binds to superhelical and cruciform DNA, and induces positive supercoils into closed circular DNA. The available evidence strongly suggests that DEK could function as an architectural protein in chromatin comparable to the better known classic architectural chromatin proteins, the high-mobility group or HMG proteins. 相似文献
997.
998.
Design, expression, and characterization of a novel targeted plectasin against methicillin-resistant Staphylococcus aureus 总被引:1,自引:0,他引:1
Ruoyu Mao Da Teng Xiumin Wang Di Xi Yong Zhang Xiaoyuan Hu Yalin Yang Jianhua Wang 《Applied microbiology and biotechnology》2013,97(9):3991-4002
A novel specifically targeted antimicrobial peptide (STAMP) that was especially effective against methicillin-resistant Staphylococcus aureus (MRSA) was designed by fusing the AgrD1 pheromone to the N-terminal end of plectasin. This STAMP was named Agplectasin, and its gene was synthesized and expressed in Pichia pastoris X-33 via pPICZαA. The highest amount of total secreted protein reached 1,285.5 mg/l at 108 h during the 120-h induction. The recombinant Agplectasin (rAgP) was purified by cation exchange chromatography and hydrophobic exchange chromatography; its yield reached 150 mg/l with 94 % purity. The rAgP exhibited strong bactericidal activity against S. aureus but not Staphylococcus epidermidis or other types of tested bacteria. A bactericidal kinetics assay showed that the rAgP killed over 99.9 % of tested S. aureus (ATCC 25923 and ATCC 43300) in both Mueller–Hinton medium and human blood within 10 h when treated with 4× minimal inhibitory concentration. The rAgP caused only approximately 1 % hemolysis of human blood cells, even when the concentration reached 512 μg/ml, making it potentially feasible as a clinical injection agent. In addition, it maintained a high activity over a wide range of pH values (2.0–10.0) and demonstrated a high thermal stability at 100 °C for 1 h. These results suggested that this STAMP has the potential to eliminate MRSA strains without disrupting the normal flora. 相似文献
999.
Hongliang Wang Xiaolan Tang Ganghua Tang Tingting Huang Xiang Liang Kongzhen Hu Huaifu Deng Chang Yi Xinchong Shi Kening Wu 《Apoptosis : an international journal on programmed cell death》2013,18(8):1017-1027
The synthetic bis(zinc(II)-dipicolylamine) (DPAZn2) coordination complexes are known to have a high specific and selective affinity to target the exposed phosphatidylserine (PS) on the surface of dead and dying cells. An 18F-labeled DPAZn2 complex (4-18F-Fluoro-benzoyl-bis(zinc(II)-dipicolylamine), 18F-FB-DPAZn2) as positron emission tomography (PET) tracer was developed and evaluated for in vivo imaging of tumor treated with a chemical agent. The in vitro cell stain studies revealed that fluorescent DPAZn2 complexes (Dansyl-DPAZn2) stained the same cells (apoptotic and necrotic cells) as fluorescein isothiocyanate (FITC) labeled Annexin V (FITC-Annexin V). The radiosynthesis of 18F-FB-DPAZn2 was achieved through the amidation the precursor bis(2,2′-dipicolylamine) derivative (DPA2) with the prosthetic group N-succinimidyl-4-[18F]-fluorobenzoate (18F-SFB) and chelation with zinc nitrate. In the biodistribution study, the fast clearance of 18F-FB-DPAZn2 from blood and kidney was observed and high uptake in liver and intestine within 90 min postinjection was also found. For the PET imaging, significantly higher tumor uptake of 18F-FB-DPAZn2 was observed in the adriamycin (ADM)-treated Hepa1-6 hepatocellular carcinoma-bearing mice than that in the untreated tumor-model mice, while a slightly decreased tumor uptake of 18F-FDG was found in the ADM-treated tumor-bearing mice. The results indicate that 18F-FB-DPAZn2 has the similar capability of apoptosis detection as FITC-Annexin V and seems to be a potential PET tracer for noninvasive evaluation and monitoring of anti-tumor chemotherapy. The high uptake of 18F-FB-DPAZn2 in the abdomen needs to optimize the structure for improving its pharmacokinetics characteristics in the future work. 相似文献
1000.
Aiping Lan Wenming Xu Hui Zhang Xiaoxiao Hua Dongdan Zheng Runmin Guo Ning Shen Fen Hu Jianqiang Feng Donghong Liu 《Neurochemical research》2013,38(7):1454-1466
We have demonstrated the neuroprotection of hydrogen sulfide (H2S) against chemical hypoxia-induced injury by inhibiting p38MAPK pathway. The present study attempts to evaluate the effect of H2S on chemical hypoxia-induced inflammation responses and its mechanisms in PC12 cells. We found that treatment of PC12 cells with cobalt chloride (CoCl2, a hypoxia mimetic agent) enhanced IL-6 secretion, nitric oxide (NO) generation and expression levels of inducible nitric oxide synthase (iNOS) and neuronal nitric oxide synthase (nNOS). L-canavanine, a selective iNOS inhibitor, partly blocked CoCl2-induced cytotoxicity, apoptosis and mitochondrial insult. In addition, 7-Nitroindazole (7-NI), an inhibitor of nNOS, also partly attenuated the CoCl2-induced cytotoxicity. The inhibition of p38MAPK by SB203580 (a selective p38MAPK inhibitor) or genetic silencing of p38MAPK by RNAi (Si-p38) depressed not only CoCl2-induced iNOS expression, NO production, but also IL-6 secretion. In addition, N-acetyl-l-cysteine, a reactive oxygen species (ROS) scavenger, conferred a similar protective effect of SB203580 or Si-p38 against CoCl2-induced inflammatory responses. Importantly, pretreatment of PC12 cells with exogenous application of sodium hydrosulfide (a H2S donor, 400 μmol/l) for 30 min before exposure to CoCl2 markedly attenuated chemical hypoxia-stimulated iNOS and nNOS expression, NO generation and IL-6 secretion as well as p38MAPK phosphorylation in PC12 cells. Taken together, we demonstrated that p38MAPK-iNOS pathway contributes to chemical hypoxia-induced inflammation and that H2S produces an anti-inflammatory effect in chemical hypoxia-stimulated PC12 cells, which may be partly due to inhibition of ROS-activated p38MAPK-iNOS pathway. 相似文献